高掺量赤泥基路基充填材料试验研究

Experimental Research on Subgrade Filling Materials with High Mixed Red Mud

本文通过拜耳赤泥、高吸水性树脂和硫铝酸盐水泥制备了高掺量赤泥基路基充填材料,研究了拜耳赤泥及高吸水性树脂掺量对充填材料凝结时间、流动性、体积稳定性、力学强度的作用关系,确定了不同龄期条件下赤泥基路基充填材料的碱浸出特性,并通过红外光谱、压汞试验、扫描电镜分析了拜耳赤泥与硫铝酸盐水泥的作用机理。试验表明,随着赤泥掺量的增加,充填材料结石体凝结时间先缩短后延长,力学强度随赤泥掺量的增加而逐渐减小。高吸水性树脂可以延缓胶凝材料的水化速率,降低其流动度,但对充填材料的体积收缩和泛碱特性有较好的抑制作用。当赤泥掺量为70%,高吸水性树脂掺量为0.4%时,充填材料28 d强度为5.2 MPa,收缩率仅为1.8%,表明赤泥基充填材料符合路基充填工程需求,其制备可以大宗量利用赤泥,减少环境污染。

This paper prepared a high mixed red mud based subgrade filling material through Bayer red mud,super absorbent polymer,and sulphoaluminate cement,and studied the effect of red mud and super absorbent polymer dosages on the setting time,fluidity,volume stability,and mechanical strength of the filling material,and determined the alkali leaching characteristics of the red mud subgrade filling material under different age conditions,and analyzed the interaction mechanism of Bayer red mud and sulphoaluminate cement by FTIR,MIP and SEM.The test shows that with the increase of the red mud content,the setting time of the filling material stone body is shortened first and then extended,and the mechanical strength gradually decreases with the increase of the red mud content.Super absorbent resin can delay the hydration rate of the gelling material and reduce its fluidity,but it has a better inhibitory effect on the volume shrinkage and efflorescence characteristics of the filling material.When the content of red mud is 70%and the content of super absorbent resin is 0.4%,the 28 d strength of the filling material is 5.2 MPa,and the shrinkage rate is only 1.8%,indicating that the filling material of the red mud base meets the requirements of the roadbed filling project,the preparation can utilize red mud in bulk and reduce environmental pollution.